Increased work connectivity and study mobility over national boundaries in recent decades has led to a shift in the kind of English as a Second Language (ESL) instruction implemented in many educational institutions. Instruction to develop learners’ general English language proficiency may appear as a time-consuming and abstract endeavour. Instead, many institutions implement English for Specific Purposes (ESP), including English for Academic Purposes (EAP) type instruction. In ESP, the aim is to help students develop the specialized academic and work-related linguistic registers they need to function in target settings where English is used as a medium of instruction or in businesses and workplace communication. A great deal of ESP research has now been conducted to build linguistic descriptions of specialized registers. Rather less research has focused on the learning of such specialized registers. This article identifies areas for a research agenda to develop an understanding of learning a specialized register. It sets out two sites for enquiry, namely, learning in a target workplace or disciplinary study setting and learning in instructed ESP, and four topics for enquiry, namely, processes of learning, conditions for learning, learning trajectories, and transfer of learning. Example tasks are suggested for research into learning in target settings.